"Hidradenitis suppurativa" is acne inversa! An appeal to (finally) abandon a misnomer.

The term "hidradenitis suppurativa" is firmly entrenched in the dermatological literature although it refers to a false pathogenetic concept. The term was historically coined based merely on the characteristic distribution of the apocrine glands and the anatomical coincidence with the disease process. At center stage is not a suppurative inflammation of the apocrine sweat glands but an occlusion of the hair follicles, comparable to acne vulgaris. Reviewing the literature on this subject, we were astonished to find that even articles that concluded that the entity represents a form of follicular occlusion still referred to it as hidradenitis suppurativa. The disorder shares histopathological and clinical aspects with acne vulgaris modified under the special circumstances of anatomical regions rich in apocrine glands. It is acne inversa because, in contrast to acne vulgaris, the disease involves intertriginous localizations and not the regions classically affected by acne. We suggest that the term "hidradenitis suppurativa" for this disease should (finally) be abandoned in favour of "acne inversa".